The existing traditional base station is generally divided into an active part and an antenna feeder part. The testing for the active part of the base station generally adopts the conduction test method, to connect a radio frequency port of the base station with a test instrument through passive components, such as, a radio frequency cable, an essential attenuation pad, a combiner, etc., to perform a radio frequency index performance test of the base station. And the testing for the antenna feeder part is proceeded in the darkroom or the outdoor far field with the wave-absorbing material, to test its space division characteristics, such as gain, directional diagram, etc. The test contents of the two parts are carried on separately.
An active antenna system (AAS) acts as a base station communication subsystem by integrating a multiple-channel transceiver and a base station antenna, it is an integrated device of the antenna and the multiple-channel transceiver, and the interface between each other is shown as an internal interface, and it is difficult to perform the radio frequency port test directly on the project, which brings challenges to the test of the active antenna system.
The active antenna system is tested by using the traditional conduction test method, and the active part and the antenna feeder part of the active antenna system need to be separated, and a coupling test interface needs to be added in the active part, which will bring the following problems:
1). the integrated topological structure of the active antenna system is destroyed; the design complexity is increased at the same time, and the coupling mode will produce the unnecessary loss;
2). this kind of coupling mode will bring some problems in a testing application, such as, there should be a high requirement on the dynamic range of the test device, etc.;
3). because of the difference among the coupling modes and coupling parameters adopted by various device manufacturers, it brings the difficulty to a unify test authentication and test specification;
4). during the testing, appropriate connectors and devices are required to be configured, and in order to gain the acceptance of the user, the test process and the authentication of the test parameter are required to be explained a lot;
5). the performance index and the spatial character of the antenna interface of the active antenna system are unable to be directly measured, and can only be calculated and converted relying on the antenna parameter index and the active part test, thus the user needs to do a large amount of work for authenticating introduced antenna parameters.
There are other test methods that can be applied to the active antenna system, such as, Over The Air (OTA) test method, which is an overall test method which can realize the active antenna system, including the spatial characteristic test and the radio frequency index testing. However, because this kind of test needs a certain test environment requirement, such as, an indoor far field test needs a darkroom of a certain size; while an outdoor far field test is apt to be influenced by the weather and the external undesired signal, which will bring the problem for both the testing cost and the testing efficiency, and to some test items, for example, test items associated with the production, etc, it is unnecessary to use the OTA.